Electric plug connection



y 8, J. A. BUCKLEY 2,248,605

' ELECTRIC PLUG CONNECTION Filed Oct. 5, 1939 Fm .1 Fig .2 Fu, .4

J f 'l IIII l A 5 Pesi/ienf INVENTOR. t/bHN/LB CKLEY ATTORNEY.

Patented July 8 1941 U ET E STAT E 5 rarer rrice 2 Claims.

My invention relates to an electric plug connection, and has for itsprincipal object means to lock the plug to the base inits relativecircuit closing position.

A further object of my invention is to provide a lock that will engageand disengage by turning movement of the plug at the time of its snugengagement with the base.

A still further object of my invention is to provide a locking meansthat will automatically function with respect to its locking feature.

A still further object of my invention is to provide, in a standard plugand base, prongs that will lock the plug and base to snug engagement aswell as make and break the current.

A still further object of my invention is to provide a locking means byaltering the shape of a standard prong; in other words, to remove aportion of the prong edges to form a hook on each thereof.

A still further object of my invention is to provide a cushion betweenthe plug and base for snug engagement of the locking feature, whichcushion.

A still further object of my invention is to provide, in some instances,a metallic keeper for the prong hook to avoid deterioration of theshoulder as a keeper, which otherwise would be of insulation material.

A still further object of my invention is to avoid additional expenseover that provided in an ordinary manufactured plug and base, the

plug insertible and operative without altering the plug and base bodystructures.

These and other objects will hereinafter be more fully explained,reference being had to the accompanying drawing, forming a part of thisspecification, in which like characters will .apply to like parts in thedifferent views.

Referring to the drawing:

Fig. 1 is a side view of the plug, being turned for a diagonal view ofthe prong, showing the hooks oppositely extending from their respectiveshanks.

Fig. 2 is a view of the pronged end of the plug, parts removed forconvenience of illustration.

Fig. 3 is a side view of the plug and base assembly.

Fig. 4 is an enlarged sectional view longitudinal of Fig. 3.

Fig. 5 is a sectional view taken on line 5-5 in Fig. 4, looking in thedirection of the arrows.

is accomplished by resilience -of the all) Fig. 6 is an end view of theplug as modified for automatic connection.

Fig. 'l is an end view of the base illustrating the position of thecircuit closing means as seen through the slots.

Fig. 8 is a side view of Fig. 6, the base engagement shown by dottedlines.

Fig. 9 is a'similar View of the plug shown in Fig. 8 and a sectionalview of the base taken on line 9-9 in Fig. 7.

Fig. 10 is a plane view of a flexible washer for the prong end of theplug.

Fig. 11 is an edge view of Fig. 10.

a Fig. 12is an enlarged view, the shanks being in section taken on linel2l2 in Fig. 9, to illustrate the angular position of the shanks as thehooks enter their respective slots.

Fig. 13 is an enlarged view of a modification of the shoulder for hookengagement.

Fig. 14 is a fragmentary view enlarged to illustrate the mounting of themodified prongs.

My invention herein disclosed consists of a locking means for anelectric plug to its base, comprising prongs and an annular elasticwasher l, the prongs consisting of a shank portion 2 and a hook 3 on theouter extremity, the hooks oppositely extending from their respectiveshanks, the prongs being rigidly carried by a plug body l, each of whichhas a screw 5 threadedly engaging in a transversely positioned plate 5'of each shank, whereby the circuit wires A are clamped firmly to theshanks by the screws in a conventional way. The structure of the base isof standard make, comprising an insulation body 6, having a metallicthreaded sleeve 1 secured thereto, a headed pin 8 axially extending intothe said insulated body portion, and a pair of oppositely disposed leafspring connectors 9, one of which is connected to the metallic sleeve,while the other is connected to the said pin, by which means when theplug prongs are inserted, as shown in Fig. 4, the electric circuit isconnected in the usual manner. In addition to such connection, myinvention provides a rigid locking means for the engagement of the plugat the instant of snug engagement of the confronting ends of said plugand base, and at which point of engagement I have provided, as abovestated, an elastic annular washer to substitute the usual asbestosconcealing disc for the end of the plug body where the prongs connect,the washer being greater in thickness than the disc, for compression, bywhich means tension is provided for snug engagement of the hooks ontheir respective shoulders B that are provided in the base as shown inFig. 5, the said hooks being engaged and disengaged by a restricted turnof the plug, it being understood that the prongs are of lesser thicknessand width than slots C in the base. Being so arranged, will provide theabove mentioned turn of the plug for the purpose set forth.

In Figs. 6, 8, and 9 is shown the prongs modifled for automaticengagement, the action of which is substantially as follows: Each prong,as above stated, has a transversely positioned base to seat in anappropriate depression formed in the plug body and being secured by aheaded pin l embedded in the body substance, the pin to loosely engagein an aperture ll, slightly funneled, as shown in Fig. 14, and to permita slight longitudinal movement thereof, a flexible washer l2, positionedon the head, will compress sufliciently for the rocking movementrequired for the prongs as they enter the slots, but resume their normalvertical position when the hook moves inward from engagement with theirrespective shoulders that are aligned with the ends of the slots. Toremove the plug, the same is accomplished by a clockwise movement,whereby the shank adjacent its base will engage on the outer end cornerof the slot, as a fulcrum to rock the hook from engagement with theshoulder sufiicient to withdraw the plug. Such turning movement mayslantingly position the shank as shown in Fig. 12, the hooks beingdisengaged. It will be seen that the prong shanks vary in length asprovided in the base structure. In other words, the shoulders referredto in the base arrangements are positioned a greater distance from theouter end inward, two specimens of which are illustrated, one of whichis shown in Fig. 4, while the other is shown in Fig. 9. In either event,the prongs are of sufiicient length to form a hook a spaced distanceinward from the outer ends of the prongs.

In Fig. 13 is shown a modification for the shoulders by virtue of ametallic element formed by a bar I3 transversely positioned to the slotand being embedded in the body substance of the base, by which means thecorner is preserved against excessive wear by metallic hook engagement.

While I have shown and described a flexible means for the prongs throughthe medium of a flexible washer at the end of the anchor pin, I do notwish to be restricted to such alone, as the plug body throughout may beof flexible substance to permit rocking movement of the prongs, and suchother modifications may be made as lie within the scope of the appendedclaims.

Having fully described my invention what I claim as new and desire tosecure by Letters Patent is:

1. In an electric plug connection, a plug and base of the classdescribed, a resilient element carried by the plug in such a way thatthe end of the base will seat thereon as outward tensioning means of thebase from the plug, a pair of lates seated on the plug, each platehaving a prong secured thereto and extending therefrom at right angle,each prong having sides and edges and a hook outwardly extending fromone edge of each prong oppositely, the direction of the extension of thehooks being clockwise with respect to rotation, a headed pin to secureeach plate to the plug rockably, there being an aperture in the plug ofa greater diameter than that of the pin and in which the pin willengage, a rubber washer rockably positioned on the pin in contact withits head, the washer to seat about the inner end of the aperture wherebythe prongs may be rocked for engagement of their hooks, the washer tonormally erect the prongs at the time of their engagement whereby thebase and plug are locked together, the base having slots spaced apartand extending inwardly and being in parallelism with the axis of thebase, said slots having sides and edges, a metallic block for each slotseated in the base adjacent its respective edge, and upon which the saidprong hooks will engage respectively when said plug and base arecompressed on the resilient element as tensioning means for the hookengagement, the edge portions at the outer end of the slots to contactwith the prong to disengage the hooks by a clockwise rotary movement ofthe plug whereby said plug and base are free to separate.

2. In an electric plug connection, a plug and base of the classdescribed, a resilient element carried by the plug in such a way thatthe end of the base will seat thereon as outward tensioning means of thebase from the plug, a pair of plates seated on the plug, each platehaving a prong secured thereto and extending therefrom at right angle,the plates to function as carrying means for the prongs and to whichelectric current conductors are attached, each prong having sides andedges and a hook outwardly extending from one edge of each prongoppositely, the direction of the extension of the hooks being clockwisewith respect to rotation, a headed pin to secure each plate to the plugrockably, there being an aperture in the plug of a greater diameter thanthat of the pin and in which the pin will engage, a rubber washerrockably positioned on the pin in contact with its head, the washer toseat about the inner end of the aperture whereby the prongs may berocked for engagement of their hooks, the washer to normally erect theprongs at the time of their engagement whereby the base and plug arelocked together, the base having slots spaced apart and extendinginwardly and being in parallelism with the axis of the base, said slotshaving sides and edges, a metallic block for each slot seated in thebase adjacent its respective edge, and upon which the said prong hookswill engage respectively when said plug and base are compressed on theresilient element as tensioning means for the hook engagement, the edgeportions at the outer end of the slots to contact with the prongs todisengage the hooks by a clockwise rotary movement of the plug wherebysaid plug and base are free to separate.

JOHN A. BUCKLEY.

